Carbonaceous ion-exchange material



Patented! Feb. 26:9,, i

,iissa amass caaeosacaons roiv-axonanan rearnnrar.

No Drawing.

Application September 23, 1938,

Serial No. semis. En ,Geany April 18,

13 Qlaiins.

amounts calculated as CaCO3- well above 0.5.

pound per cubic foot of granular substance, being durable under anindefinite number of alternat- 5 ing treatments of flowing water and ofregeneration by flows of dilute strong acid, not changing in exchangeactivity after long periods of use with loss of S03; said compositionbeing the product of reaction of granulated humic material of the natureof wood, peat, lignite, coals and cokes with S0: vapors; all as morefully hereinafter set forth and as claimed;

In a prior, copending application, Ser. No.

. 10,127, filed March 8, 1935, I have disclosed and claimed processes ofmaking improved zeolites by sulfating treatments of humic carbonaceoussubstances and various methods of using such carbonaceous zeolites forabstracting the bases of salts dissolved in water, as in hard water orsoft- 0 ened water, and for exchanging such bases for other bases. Inthe manufacture of sulfated humic zeolites, as described in saidcopending application, a member of the coal group of minerals containinghumic matter, such as lignite or :5 bituminous coal, is granulated andtreated with an ample amount of 'a strong sulfuric acid reagent, H2304,the fuming acid, pyrosulfuric acid, the anhydride 803 etc. In thetreatment the hydrocarbons of the coal are oxidized and sul- L0 fated,forming insoluble sulfonic acids and sulfuric acid esters with evolutionof S02. The temperature of the reacting mass rises and when thesuliating action ceases and excess acid is removed, the washed productis a rugged, granu- L5 lar hydrogen zeolite of high exchange value,

highly useful in base abstraction with acid regeneration and also inbase exchange with salt regeneration.

Pervious beds of these granular acidic zeolites 30 are durable underrepeated use and regeneration as in a zeolite water softener of the wellknown type; Such beds are particularly resistant to repeated alternateflows of water containing carbonate alkalinity and, dilute strong acidfor re- 55 generation. The ruggedness and durability of the sulfatedhumic zeolites and their high. exchange capacity have led to greatimprovement in the technique of water softening in particular and ofmetathetical exchange processes in eneral.

I have found that the reaction product of bituminous coal of highvolatile content, or similar humic material, lignite, anthracite, etc.and gaseous SO: forms an ion-exchange zeolite having in marked degreethe desired combination of ruggedness and durability with great exchangecapacity. A sulfated humic zeolite of high capacity for softening waterresults from passing S03 vapors into contact with granular bituminouscoal and subsequently washing with water. A given quantity of coalreacts with S0: in quantity several times the weight of the coal andwhen the reaction is complete, removal of excess acid leaves a sulfatedproduct having the desired properties in superlative degree. During thereaction, S02

' is evolved and the coal absorbs a great excess of of bituminous coal,as described, has an operat-.

ing exchange value of the order of to 11 kilograins of hardnessexpressed as CaCOa per cubic foot when regenerated with about 4 poundssalt per cubic foot; that is to say, it can be depended upon to take upfrom flowing water bases in amounts equivalent to 1.5 pounds or more02.00: per cubic foot of the granular sulfated product, this being asalt efliciency about 44 per cent of theoretical.

Granular humic materials treated with S0: may be converted to strongzeolites having an exchange capacity less than the maximum by using lessS03 and a shorter time in the sulfating treatment.

not materially lower the regenerating eiilciency in metathetical ionexchange. In the manufacture, the sulfur content and exchange value ofthe product is regulated by the relative quantity of SO: used in thetreatment. a

In producing the reaction product of bitumi- However, the smallerexchange capacity,

which may be desirable for some purposes, does nous coal with gaseousS03, it is advantageous drained from the sulfated coal. then washedthoroughly with water until it notion proceeds with evolution of heatand some disintegration of the coal granules. The temature should not beallowed to rise above 30 C. is usually advantageous to cool the vesselso to hold the temperature of reaction below 1' C. ihe reaction requiresseveral hours time d the exchange value and sulfur content of onesulfated material increase as the reaction roceeds to completion. Thematerial then is iashed and the excess $03 which has been taken isremoved as sulfuric acid. The washed fully sulfated product usually hasa sulfur content equivalent or to 20 per cent S03 on a dry basis anexchange value above 11,000 grains. An exchange value one half of thismay be associated with a sulfur content of 4 to 6 per cent S03. In thesulfating reaction, which is a vigorous one, the coal is disintegratedto some extent and, as

above stated, it is usually advantageous to have the granules of rawcoal before treatment considerably larger than the'granule desired. Forexample, if the raw coal is sized to pass a 10-mesh screen and to beheld on a 20-mesh screen, then the product of the S03 treatment will befor the most part held on a 40-mesh screen; the losses in fines beingthus minimized. A 10-40 mesh size of sulfated granule is convenient andadvantageous. Thus the fineness of the product is controlled as desiredby the sizing of the raw coal.

In a specific example of the invention, four cubic feet of granulatedbituminous coal containing 30 per cent volatile matter and weighing 160-pounds with less than 2 per cent moisture wereplaced in a lead-linedrotary drum equipped with fiights for agitating purposes and S03 vapor,from a liquid container under pressure, and diluted with dry air to aconcentration of 10 to per cent S03 by volume was passed into the drumfor about hours; the revolving drum being sprayed with water to keep thetemperature below 100 C. The efliuent gases containing considerableamounts of S02 and negligibly small quantities of S03 were scrubbed withwater. In the reaction a total of about 600 pounds S03 was used. Thecoal swelled in volume from 4 to 8 cubic feet and increased in weightfrom 160 to'440 pounds. The coal took up 3.6 pounds SO: per pound coal,the sulfated coal, before washing, containing 58 per cent S03. After thesulfating reaction was complete, the product was sprayed with water andabout 500 pounds of 4.0 per cent sulfuric acid The product was longergave up acidity. The washed and drained product containing 43 per centmoisture weighed 250 pounds. It contained 15 per cent S03 on a dry basisand showed by test an operating exchange value of 11,300 grains 'CaCOaper cubic foot under regeneration with 4 pounds NaCl. Samples ofmaterial taken from the revolving drum during the sulfating operationshowed a gradual increase of SO: content and-of exchange value. Forexample, about midway of the total time, when the weight of acidanhydride used was about half the total, the S03 content (beforewashing) was 28 per cent, after washing about 7 per cent and theexchange value (after wash arenoso ing) was M00: grains with 4 poundssalt per cubic foot.

In the sulfating, as described, in a rotating drum, the temperature atthe gas intake end was considerably higher than that at the exit untilthe reaction was nearly complete. It is possible to utilize thecountercurrent principle by passing the coal through a long revolvingdrum in one direction and diluted S03 gas in the opposite directionthrough the drum. So doing, the temperature is equalized and consumptionof SO;

.' distinguished by its high exchange activity and great durability inuse. The product can be used for an indefinitely long time as a perviousbed in a water softener without signs of physical deterioration or lossof chemical activity. However, in continued use for treatment of flowingwater with occasional regenerating flows of dilute acid or of saltbrine, there is a gradual loss of sulfur content without loss ofexchange activity.

This application is a continuation-inpart of my application Serial No.10,127, filed March 8, 1935.

What I claim is:

1. As a new manufacture for use in treating water by ion-exchange, areaction product of gaseous SO: and a carbonaceous material selectedmeshes to the linear inch and held by a 40 mesh screen.

4. An ion-exchange material according to claim 2 in which the sulfurcontent calculated as S0: is from 10 to 20 per cent.

5. An ion-exchange material according to claim 2 having an operatingexchange value above 10,000 grains CaCQz equivalent per cubic foot whenregenerated with 4 pounds salt.

6. A process of making an ion-exchange material which comprises passingvapors of $03 in contact with granules of a carbonaceous materialselected from the group consisting of wood, peat, lignite, coals andcokes, preferably at temperatures under 100 C.

7. A process of making an ion-exchange material which comprises reactinggranules of a carbonaceous material selected from the group consistingof wood, peat, lignite, coals and cokes with S03 vapors until thematerial has taken up a substantial quantity of excess S03, and washingout excess $03 with water as sulfuric acid.

8. A process of making an acid resistant water insoluble granularion-exchanging material comenemas 9. A process as defined in claim 8 in.which the carbonaceous material is reacted with more than an equalweight of gaseous S03.

10. A process as defined in claim 8 in which the carbonaceous materialis granulated .to a size such that a major portion of it is retained ona 20 mesh screen before being reacted with the V gaseous SOs.

11. A process as defined in claim 8 in which the gaseous S03 is dilutedwith another gas .to control the rate of reaction of the S03 with thecoal.

12. A process as defined in claim 8 in which the carbonaceous materialbeing reacted with the gaseous S03 is cooled during the reaction.

Patent No. 2,191,059.

orro LIEBKNE GET;

OTTO LIEVBKNECHT.

- CERTIFICATE OF CORRECTION.

r ry '20, 19LL0.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2second column, line 72, claim 8, strike out the word "sulfated"; andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this.9th day of April, A. D. 19in.

(Seal) Henry Van Arsdale, Acting Commissioner of Patents CERTD'ICATE OFCORRECTION. Patent No. 2,191,059. February '20, 19110.-

OTTO LIEBKNECHT; It is hereby certified that error appears in theprinted specification of. the above numberedpatent requiring correctionas follows: Page 2, sec- 4 0nd 001mm, line 72, claimB, strike out theword "sulfated"; and that the said Letters Patent should be read withthis correction therein that the same may conform to the record of thecase in the Patent Office.

Signed and sealed this.9th day of April, A. D.- 19LLO.

I Henry Van Arsdale, (Seal) Acting Commissioner of Patents

